1. Field of the Invention
The invention relates in general to a flexible card with display function, and more particularly to a flexible public transportation card with display function.
2. Description of the Related Art
Along with the advance in technology, many transactions and payments are gradually processed by conventional integrated circuit (IC) cards. The IC cards are such as credit cards, finance cards, telephone cards and so on. According to the difference in communication interface, the IC cards may have three types, namely, the contact mode, contactless mode, and the dual interface mode.
The IC cards may further be divided into two categories, namely, the smart card and the memory card. The smart card has a control mechanism containing an 8-bit, 16-bit or 32-bit micro-processor with appended encryption processing such as DES, RSA. The memory card contains a memory and a simple logic circuit. The memory is such as a read-only memory (ROM) or a non-volatile memory, and has a capacity of such as 4K, 8K, 16K . . . 1M bytes.
The contactless and dual interface mode IC cards may further be divided into three categories according to the different communication protocols, namely, the type A, the type B and the Felica type. The type A and the type B are conformed to the proximity ISO 14443 standard, and the Felica type is conformed to the Sony Corporation standard, and the type A. type B and the Felica type all have a telecommunication distance of about 0-10 cm. The dual interface mode, being a combination of the contact and contactless modes, may further be divided into two categories, namely, the single chip type and multiple chip type.
The conventional smart card with display function comprises a display, an antenna, a communication interface, a micro-processor, a display driving circuit, a boost circuit, a rectification voltage-stabilizing circuit, a non-volatile memory, a contactless RF smart card integrated circuit and a contact smart card. The IC communication interface may be a contactless radio frequency (RF) interface or a contact communication interface.
For the contactless communication interface, the antenna is disposed in the contactless RF smart card integrated circuit. The antenna receives an RF signal from an external card reader. The communication interface performs RF demodulation on a coupled signal. On the other hand, the rectification voltage-stabilizing circuit generates a DC power from the coupled signal and further supplies the internal elements with necessary voltages.
After the micro-processor receives a signal from the communication interface, data is stored in the memory, and the display driving circuit may further convert the data into a display driving signal for the user to check. The micro-processor may also send a response signal to the antenna via the communication interface, and the antenna further sends the signal to the external card reader. The boost circuit converts the DC power generated by the rectification voltage-stabilizing circuit into higher voltages, and the display driving circuit further converts the higher voltages into a display driving signal.
However, the entire operation of the smart card with display function from the start of communication to the end of display frame takes at least 1 second. In the field of communication with the time being pressing, only 0.2 to 0.6 seconds are available for generating electricity from the electromagnetic induction with an external card reader. Within such a short power supply time, the smart card with display function is unable to complete system operation and frame display.